// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/parsing/parsing.h"

#include <memory>

#include "src/ast/ast.h"
#include "src/objects-inl.h"
#include "src/parsing/parse-info.h"
#include "src/parsing/parser.h"
#include "src/parsing/scanner-character-streams.h"
#include "src/vm-state-inl.h"
#include "src/zone/zone-list-inl.h" // crbug.com/v8/8816

namespace v8 {
namespace internal {
    namespace parsing {

        bool ParseProgram(ParseInfo* info, Isolate* isolate)
        {
            DCHECK(info->is_toplevel());
            DCHECK_NULL(info->literal());

            VMState<PARSER> state(isolate);

            // Create a character stream for the parser.
            Handle<String> source(String::cast(info->script()->source()), isolate);
            isolate->counters()->total_parse_size()->Increment(source->length());
            std::unique_ptr<Utf16CharacterStream> stream(
                ScannerStream::For(isolate, source));
            info->set_character_stream(std::move(stream));

            Parser parser(info);

            FunctionLiteral* result = nullptr;
            // Ok to use Isolate here; this function is only called in the main thread.
            DCHECK(parser.parsing_on_main_thread_);

            result = parser.ParseProgram(isolate, info);
            info->set_literal(result);
            if (result == nullptr) {
                info->pending_error_handler()->ReportErrors(isolate, info->script(),
                    info->ast_value_factory());
            } else {
                info->set_language_mode(info->literal()->language_mode());
                if (info->is_eval()) {
                    info->set_allow_eval_cache(parser.allow_eval_cache());
                }
            }
            parser.UpdateStatistics(isolate, info->script());
            return (result != nullptr);
        }

        bool ParseFunction(ParseInfo* info, Handle<SharedFunctionInfo> shared_info,
            Isolate* isolate)
        {
            DCHECK(!info->is_toplevel());
            DCHECK(!shared_info.is_null());
            DCHECK_NULL(info->literal());

            // Create a character stream for the parser.
            Handle<String> source(String::cast(info->script()->source()), isolate);
            isolate->counters()->total_parse_size()->Increment(source->length());
            std::unique_ptr<Utf16CharacterStream> stream(
                ScannerStream::For(isolate, source, shared_info->StartPosition(),
                    shared_info->EndPosition()));
            info->set_character_stream(std::move(stream));

            VMState<PARSER> state(isolate);

            Parser parser(info);

            FunctionLiteral* result = nullptr;
            // Ok to use Isolate here; this function is only called in the main thread.
            DCHECK(parser.parsing_on_main_thread_);

            result = parser.ParseFunction(isolate, info, shared_info);
            info->set_literal(result);
            if (result == nullptr) {
                info->pending_error_handler()->ReportErrors(isolate, info->script(),
                    info->ast_value_factory());
            } else {
                info->ast_value_factory()->Internalize(isolate);
                if (info->is_eval()) {
                    info->set_allow_eval_cache(parser.allow_eval_cache());
                }
            }
            parser.UpdateStatistics(isolate, info->script());
            return (result != nullptr);
        }

        bool ParseAny(ParseInfo* info, Handle<SharedFunctionInfo> shared_info,
            Isolate* isolate)
        {
            DCHECK(!shared_info.is_null());
            return info->is_toplevel() ? ParseProgram(info, isolate)
                                       : ParseFunction(info, shared_info, isolate);
        }

    } // namespace parsing
} // namespace internal
} // namespace v8
